1. Field of the Invention
The present invention relates to a novel organogermanium compound, a salt thereof, process for the preparation of the same as well as a use of the compound as an effective ingredient for pharmaceutical preparations.
2. Related Arts
Organogermanium compounds have been watched with great interests in recent years, since those show various and attractive pharmacological activities, so that various study reports have been issued, as stated below.
For instance, it has been reported that a compound (known in the art as "Y-9577") of the formula ##STR3##
wherein Et is ethyl and Me is methyl, shows an antiinflammatory activity [Jap. Pat. Nos. Sho 56-45492(A), 56-99418(A), 56-99491(A) and 56-108708(A)]. It has also been reported that another compound (known in the art as "Spirogermanium") of the formula ##STR4## wherein Et and Me have the meanings as referred to, shows an anti-cancer or antitumor activity ["Cancer Res.", Vol. 42, page 2852 (1982)].
Some of the present inventors have also studied on some organogermanium compounds and reported that 3-oxygermylpropionic acid polymer shows an excellent immunomodulating activity [Jap. Pat. No. Sho 61-151123(A) corresponding to U.S. Pat. No. 4,889,715 and EP No. 0186505 (A2)].
In spite of that various pharmacological activities have been reported on various organogermanium compounds, as referred to, the quantitative structure-activity relationships of organogermanium compounds and mechanism of pharmacological action have not yet been fully elucidated.
When the prior arts as referred to and experiences of the present inventors have been taken into consideration, it is so estimated on organogermanium compounds that a difference in structure exerts great influences on a kind of pharmacological activity and intensity thereof. Paradoxically speaking, this means that a preparation of novel organogermanium compound different from the conventional compounds in its structure and investigation of its pharmacological activities not only contribute to an elucidation of quantitative structure-activity relationships and mechanism of pharmacological action, but also give an expectancy of new pharmacological activity or an increase in activity, even though the kind of activity is same with that in the known organogermanium compounds.